Method and apparatus for interrupting a transmission of a multicast signal

ABSTRACT

A method and apparatus for interrupting a transmission of a multicast signal includes a common channel selector ( 106 ) coupled to a receiver ( 102 ) to receive common channel information ( 116 ) therefrom. A repetition value calculator ( 108 ) receives measurement occasion information ( 118 ) from the common channel selector ( 106 ) to calculate a repetition factor (120). A system frame number comparator ( 110 ) determines if a channel measurement occasion ( 128 ) should be performed based on the repetition factor ( 120 ), a common identifier ( 124 ) and a largest common channel transmission time interval ( 122 ). The method and apparatus further includes a measurement occasion generator ( 112 ) coupled to the system frame number comparator ( 110 ), wherein if a measurement occasion is to be performed, a measurement occasion command signal ( 126 ) is provided to the measurement occasion generator ( 112 ) and the measurement occasion generator generates the channel measurement occasion ( 128 ).

RELATED CO-PENDING APPLICATIONS

This application is a divisional application of co-pending applicationSer. No. 10/704,931, filed on Nov. 10, 2003, entitled “METHOD ANDAPPARATUS FOR INTERRUPTING A TRANSMISSION OF A MULTICAST SIGNAL” havinginventors Richard C. Burbidge et al., owned by instant Assignee and isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to a mobile communicationapparatus and method and more specifically to multicast signaltransmission in a wireless network for serving a plurality of mobilecommunication devices.

BACKGROUND OF THE INVENTION

Typically a wireless network is configured to transmit on a number ofcommon and dedicated channels. The common channels carry information fora plurality of mobile devices either simultaneously, as through abroadcast, or individually, through independent addressing means. Mobiledevices may also be configured to receive a multicast or broadcastsignal on a common channel, wherein the multicast or broadcast signal isa message signal generated by a central communication source, such as acomputer server, and transmitted simultaneously to a plurality of mobiledevices. If a multicast or broadcast service is required to re-transmitthe multicast or broadcast information on an individual user basis or toa subset of users, this results in a loss of efficiency for themulticast or broadcast service.

In accordance with third generation partnership project (3GPP)standards, a Universal Mobile Telephoning System (UMTS) network allowsoperation in four different states in connected mode, CELL_DCH,CELL_FACH, CELL_PCH and URA_PCH. In the CELL_FACH state, the mobilemonitors a common physical channel based on some pre-defined selectionrules, identified by one or more channelization codes. The network maymap multiple common data channels onto the same common physical channel.The different common channels can be configured differently so as toprovide different quality of transmission, typically for differentservices, over the same common physical channel.

The mobile device typically monitors one of the common channels on anassigned common physical channel. When in the CELL_FACH state, a mobiledevice is generally available to receive information across a commonchannel assigned by its network, but must periodically suspend receptionof signals on the common physical channel associated with the commonchannel. These intervals where common physical channel reception issuspended are usually termed measurement occasions. During a measurementoccasion, the communications device tunes its receiver to a differentfrequency for purposes such as measurement of other common physicalchannel frequencies within the same system or different system. When ameasurement occasion occurs, the mobile device typically cannot receiveincoming information on the currently allocated common physical channel,due to inherent limitations in receiving two physical channelsdifferentiated in frequency.

Generally, a network seeks to evenly distribute the timing ofmeasurement occasions within a coverage area. This aids in efficientusage of the common physical channels. A typical UTMS network knows thetiming of the measurement occasions for the mobiles in a particularcell. Under current UMTS specification 3GPP TS 25.331, the networkdetermines when these measurement occasions are to occur and does nottransmit data directed to a particular mobile during the time intervalswhen that mobile should be in a measurement occasion.

Since different mobile devices will conduct measurement occasions atdifferent times based on their individual identities, the network willnot be able to reliably transmit a multicast transmission in anefficient manner that can be completely received by all subscribedmobile devices. Furthermore, if a multicast signal is transmitted on aseparate common physical channel, the conventional common data channelmay be underutilized and also messages may not be delivered to themobile device if the mobile device chooses to receive the multicasttransmission instead of the transmission destined for it on theconventional common data channels.

Thus, there is a potential conflict between when a mobile device canperform a measurement occasion and the reliable reception of a multicastor broadcast signal. Because each mobile device can perform itsmeasurement occasion at different time intervals, or during differentsystem frames, the multicast or broadcast signal may not be received bymobile devices performing a measurement occasion during a period whenthe multicast or broadcast is transmitted. Also, if the length of themulticast or broadcast signal is more than one system frame, thisincreases the number of mobile devices that cannot receive the completemulticast or broadcast signal. Thus, there is a desire to allocatemeasurement occasions of mobile stations within a coverage area toreduce their impact on multicast or broadcast service reliability andefficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood with reference to thefollowing drawings wherein:

FIG. 1 illustrates a block diagram of a wireless mobile device accordingto one embodiment;

FIG. 2 illustrates a graphical representation of a system frame and atransmission time interval;

FIG. 3 illustrates a graphical representation of an example of aplurality of common channels mapped onto a common physical channel;

FIG. 4 illustrates a graphical representation of an example of aplurality of mobile cells relative to a network;

FIG. 5 illustrates a flowchart of a method for interrupting atransmission of a multicast signal according to an embodiment;

FIG. 6 illustrates a flowchart of a method for interrupting thereception of a multicast signal according to an embodiment;

FIG. 7 illustrates a flowchart of a method for interrupting atransmission of a multicast signal according to another embodiment;

FIG. 8 illustrates a graphical representation of an example of aplurality of system frames;

FIG. 9 illustrates a graphical representation of an example of aplurality of system frames of a common channel carrying user dataassigned to sub-groupings;

FIG. 10 illustrates a graphical representation of an example of amulticast channel carrying multicast data illustrating a single timeinterval of interruption of the multicast transmission;

FIG. 11 illustrates a graphical representation of an example of aconventional common data channel with a single sub-group designated forperforming a measurement occasion; and

FIG. 12 illustrates a graphical representation of an example of aconventional common data channel with multiple sub-groups capable ofperforming measurement occasions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The method and apparatus for interrupting a transmission of a multicastsignal uses a common identifier for the mobile devices within a coveragearea that receive a particular multicast service. As used herein, theterm “multicast” encompasses the term “broadcast.” The common identifierindicates the time intervals where transmission of the multicast signalshould be interrupted so the mobile devices can perform measurementoccasions without missing portions of the multicast signal.

In one situation, a network configures multiple common data channels ona common physical channel. A common channel is set aside for multicasttransmissions, referred to as a common multicast channel. Other commonchannels, referred to as conventional common data channels, are used fortransmitting dedicated data, among other information, to a wirelessmobile device. However, since both channels are mapped to the samecommon physical channel, any time the mobile device interrupts theconventional common data channel reception for a measurement occasion,the mobile device will also stop receiving the multicast transmissionbeing transmitted on the multicast channel. Thus, one embodimentinterrupts transmission of a multicast signal on a common multicastchannel so that no information is missed when the mobile is performing ameasurement occasion.

In another embodiment, the network further sub-divides the timeintervals where the multicast signal is interrupted. The sub-timeintervals are based on further sub-grouping of the mobile devicesreceiving the multicast transmission. In one embodiment, this furthersub-grouping can be based on: the individual multicast service identity,in the case of multiple multicast transmissions being transmittedsimultaneously to different mobile devices in the cell; a cell or UTRANregistration area specific unique identifier; and/or any other suchidentity allowing the network to sub-divide the mobile devices intogroups.

A method and apparatus for interrupting a transmission of a multicastsignal includes a common channel selector coupled to a receiver, suchthat the common channel selector receives channel information therefrom.The method and apparatus further includes a repetition value calculatorreceiving measurement occasion information from the common channelselector to calculate a transmission interruption time intervalrepetition factor. A system frame number comparator is coupled to therepetition value calculator and the common channel selector, wherein thesystem frame number comparator determines if a measurement occasionshould be performed based on the repetition factor, a common identifierand a largest common channel transmission time interval. The method andapparatus further includes a measurement occasion generator coupled tothe system frame number comparator, wherein if a measurement occasion isto be performed, a measurement occasion command signal is provided tothe measurement occasion generator and the measurement occasiongenerator generates a channel measurement occasion.

More specifically, FIG. 1 illustrates a wireless mobile device 100including a receiver 102 having an antenna 104, a common channelselector 106, a repetition value calculator 108, a system frame numbercomparator 110 and a measurement occasion generator 112. Thesefunctional blocks may represent executable program instructions,individual processors, application specific integrated circuits, digitalsignal processors, microprocessors, firmware, micro-controllers, statemachines, or any other recognized operational component or componentcapable of executing program instructions wherein the programinstructions may be disposed on a ROM, RAM, EEPROM, compact disk,digital versatile disk, optical medium, or any other volatile ornon-volatile storage medium. Examples of a wireless mobile device 100are: a radio, a cellular telephone, a smart phone, a personal digitalassistant with wireless transceiver, a personal computer with a wirelessreceiver, or any other suitable wireless device. Note that the receiver102 will often be part of a transceiver in a communication device.

In one embodiment, the receiver 102 receives an incoming common physicalchannel signal 114 via the antenna 104. The receiver 102 provides commonchannel information 116 to the common channel selector 106. As discussedabove, the common channel information 116 includes broadcastinformation, system parameter information, multicast transmissions, orany other suitable information as recognized by one having ordinaryskill in the art.

The common channel selector 106 performs various operations including,but not limited to, the extraction of measurement occasion information118 from the common channel information 116. The common channel selectoris operative to also select one or more of the common channels on theincoming common physical channel. In one embodiment, the measurementoccasion information 118 may be a common channel measurement occasioncycle length coefficient, commonly referenced as “k”. The measurementoccasion information 118 is provided to the repetition value calculator108 such that the repetition value calculator 108 may calculate arepetition factor 120. In one embodiment, the repetition factor 120 maybe the measurement occasion cycle length which is determined by thecalculations of two to the power of the measurement occasioninformation, k.

The common channel selector 106 also determines from the common channelinformation 116 a largest common channel transmission time interval 122.The largest common channel transition time interval 122 represents thelargest transmission time interval from amongst all of the commonchannels mapped onto the corresponding common physical channel fromwhich the mobile device 100 receives the transmission 114. In oneembodiment, the largest common channel transmission time interval 122 isrepresented as the factor N.

Within the mobile device 100, the system frame number comparator 110receives the repetition factor 120 from the repetition value calculator108, the largest common channel transmission time interval 122 from thecommon channel selector 106 and a common identifier 124. In oneembodiment, the common identifier 124 is a radio network temporaryidentifier. The common identifier 124 is provided to the mobile device100 through the receiver 102, and the common identifier 124 is providedprior to delivering a multicast service to the mobile device 100.

The system frame number comparator 110 determines if a measurementoccasion should be performed. The system frame number comparator 110calculates the timing of the measurement occasion using the repetitionfactor 120, the largest common channel transmission time interval 122and the common identifier 124. The timing of the measurement occasionmay be determined in accordance with known common channel measurementoccasion calculations using the common ID 124 in lieu of a cell radionetwork temporary ID, such as a C_RNTI.

Based on a determination of the system frame number comparator 110, ifit is determined that a measurement occasion may be performed, thesystem frame number comparator 110 generates a measurement occasioncommand signal 126, which is provided to the measurement occasiongenerator 112. The system frame number comparator 110 may determine,based on the common identifier, if a measurement occasion should beperformed for any of multiple multicast services or for a singlemulticast service. The measurement occasion generator 112 thereupongenerates a channel measurement occasion 128, in accordance with knownchannel measurement occasion procedures. Therefore, the mobile device100 may interrupt the reception of a multicast signal during a timeinterval determined by the system frame number comparator 110 for theperformance of channel measurement occasions 128.

Furthermore, the mobile device 100 may operate in accordance with acorresponding network (not shown) such that the mobile device 100 doesnot miss any multicast data provided across a multicast channel due toperforming a channel measurement occasion 128. Moreover, as discussed ingreater detail below, the mobile device 100 also determines, based onthe comparison of the system frame number comparator 110, whether themobile device 100 may read conventional common data channel data duringa time interval designated by a network for interrupting transmission ofdata on the multicast channel.

FIG. 2 illustrates a graphical representation of a portion of aplurality of system frames 200 designated by a single frame 202 relativeto a transmission time interval 204. In the embodiment displayed in FIG.2, the transmission time interval 204 has a length of four times theframe 202. Although, as recognized by one having ordinary skill in theart, the ratio of the transmission time interval 204 to the frame 200may be any suitable number as defined by a frame 202 in accordance withstandard transmission timing, such as a ten millisecond frame.

FIG. 3 illustrates the mapping of multiple common channels 300, 302 and304 to a single common physical channel 306, such as an SCCPCH(Secondary Common Control Physical Channel) of a UMTS system. The commonchannels 300, 302 and 304 may be conventional common data channels, suchas a FACH, for carrying non-multicast data or may be multicast commonchannels, such as a multicast FACH, for carrying multicast data.Therefore, with respect to FIG. 1, the receiver 102 may receive thecommon physical channel 306 and the common data channel selector 106determines the largest common transmission time interval 122 from thethree common channels 300, 302 and 304. As recognized by one havingordinary skill in the art, FIG. 3 illustrates a mapping of three commonchannels to a common physical channel 306, although any suitable numberof common channels may be mapped thereon.

FIG. 4 generally illustrates a network 400 in communication with aplurality of cells 402, 404, 406 and 408. As understood by one havingordinary skill in the art, the cells 402, 404, 406 and 408 designate ageographic area where mobile devices can perform wireless communicationbetween corresponding base stations 410, 412, 414 and 416 respectively.In a typical embodiment, the network 400 communicates with the basestations 410, 412, 414 and 416 via a communication link 418, 420, 422and 424, respectively. These communication links 418, 420, 422 and 424may be a communication link such as, but not limited to, a T1connection, a wireless connection, or any other suitable communicationconnection as recognized by one having ordinary skill in the art.

The representative cell N 408 is shown with a greater level of detailhaving a plurality of mobile devices 430, 432, 434 and 436. Each ofthese mobile devices, in one embodiment, correlate to the mobile device100 of FIG. 1 for communicating with the base station 416. The network400 may provide conventional common data channel data and multicast dataacross different common channels within a common physical channel to themobile devices 430, 432, 434 and 436 within the designated cell 408. Incoordination with the mobile device interrupting reception of amulticast signal, the network 400 also performs correspondingfunctionality for the interruption of the transmission of the multicastsignal on the multicast channel.

The functionality of the network 400 may be performed by one or moreprocessors executing program instructions, applications specificintegrated circuits, digital signal processors, microprocessors,firmware, micro-controllers, state machines, or any other recognizedoperational components capable of executing program instructions whereinthe programming instructions may be disposed on a ROM, RAM, EEPROM,compact disk, digital versatile disk, optical medium, or any othervolatile or non-volatile storage medium.

In one embodiment, the network 400 of FIG. 4 performs the operationsdefined by the steps of the flowchart of FIG. 5. The method forinterrupting transmission of a multicast signal 500 includes determininga common identifier for a plurality of mobile devices on a commonchannel, step 502. A common identifier may be a radio network temporaryID specific to a multicast transmission or may be any other suitableidentifier recognized by one having ordinary skill in the art. In oneembodiment, the common identifier may be a single common identifier fora plurality of multicast services, such as different multicasttransmissions or different services. Whereas, in another embodiment, thecommon identifier may be restricted to a single multicast service suchthat if there are a plurality of multicast services, this wouldnecessitate a plurality of common identifiers.

The next step, step 504 is sending the common identifier to theplurality of mobile devices. With respect to FIG. 4, the commonidentifier may be transmitted from the network 400 to the base station416 such that it is provided to the mobile devices 430, 432, 434 and 436via wireless transmissions. In one embodiment, the common identifier maybe provided to the mobile device through a system broadcast, where thesystem broadcast is any suitable broadcast including system informationor other means for providing information to the mobile. In anotherembodiment, the common identifier may be provided to the mobile devicethrough a dedicated message addressed to the mobile device. The commonidentifier may be a multicast radio network temporary identifier, whichis specific to the multicast transmission and temporary for the durationof the multicast transmission.

The next step is transmitting the multicast signal on a common channel,step 506. As discussed above with regard to FIG. 3, the common channel300, 302 or 304 may be mapped onto a common physical channel 306 thatcontains multicast information thereon. In one embodiment, the multicastsignal may be transmitted on one of a plurality of common channelsmonitored by multiple communication devices. Thereupon, step 508 isinterrupting transmission of the multicast signal during a time intervaldetermined by the common identifier. Similar to the above discussionregarding the system frame number comparator of FIG. 1 determining thetime interval for a measurement occasion, the time interval may bedetermined using the largest common channel transmission time interval,a repetition factor, k, and the common ID. Thereupon, the method iscomplete, step 510.

In another embodiment, the method further includes the identification ofa subgroup of mobile devices from the multiple mobiles device, such asillustrated in step 512 representing another embodiment of the method ofFIG. 5. For example, using FIG. 4 as a reference, the mobiles 430, 432,434 and 436 may be further grouped into subgroups, such as the mobiledevices 430, 432 in group A and the mobile devices 434, 436 in group B.The mobile devices may be grouped using a mobile specific identifier,which as recognized by one having ordinary skill in the art is assignedto the mobile device when it accesses the common channel state. In oneembodiment, the mobile specific identifier is a cell radio networktemporary identifier (C_RNTI).

The method further includes selectively transmitting one or moreconventional common data channel signals to the mobile devices of aspecified subgroup during the time interval designated for aninterruption of the multicast signal, such as illustrated in step 514representing another embodiment of the method of FIG. 5. In oneembodiment, the conventional common data channel signal and the commonmulticast channel signal are mapped onto a common physical channel, suchas illustrated in FIG. 3. Whereas, in another embodiment, theconventional common data channel signal and the common multicast channelsignal are mapped onto different common physical channels.

In one embodiment, the mobile specific identifier may be used toidentify a particular mobile device within a coverage area. In theembodiment where the mobile specific identifier is a C_RNTI, the mobilespecific identifier may identify mobile devices within a particularcell. In this embodiment, the mobile specific identifier is assignedwhen the mobile enters the common channel state, and is associated witha particular cell. Furthermore, the mobile specific identifier mayidentify a particular mobile device in a radio coverage area, such as aUTRAN registration area.

FIG. 6 illustrates a flowchart of the steps for a method of interruptinga reception of a multicast signal in a wireless communication device.The method begins, step 600, by obtaining a common identifier, step 602.As discussed above with respect to FIG. 1, the common identifier may bea temporary identifier provided by the network. In one embodiment, thecommon identifier may be obtained through a broadcast message. Inanother embodiment, the common identifier may be obtained through adedicated message addressed to the wireless communication device.

The next step, step 604 is receiving a multicast signal. The multicastsignal may be provided on the common multicast channel, wherein themulticast signal may include multicast broadcast information. Thereupon,the next step is interrupting the reception of the multicast signalduring a first time interval based on the common identifier, step 606.As such, the method is complete, step 608.

As discussed above with regard to FIG. 1, the system frame numbercomparator 110 determines the timing of a measurement occasion based onthe largest common channel transmission time interval 122, therepetition factor 120 and the common ID 124. When the channelmeasurement occasion may occur, the reception of the multicast signal isinterrupted such that the channel measurement occasion may be performed.It is also noted that the term interrupting herein may further includesimply receiving no information on a common multicast channel in theevent that a multicast signal is not currently being transmitted.Moreover, the time interval may be determined by a repetition factorassigned to the wireless communication device, wherein the repetitionfactor is determined based on common channel information.

In one embodiment, the method of FIG. 6 further includes performing ameasurement occasion during the time interval. Because the reception ofthe multicast signal has been interrupted, the mobile device may makethe appropriate measurement occasion during the time interval withoutany data loss. Although, as discussed in further detail below, if thereexists a timing difference between the multicast frame period and theconventional common channel frame period, the mobile device may receivea conventional channel transmission during a portion of the timeinterval.

In another embodiment of the steps of FIG. 6, the method forinterrupting a reception of a multicast signal may further includeobtaining a mobile specific identifier. As discussed above with regardsto FIG. 5, the mobile specific identifier may be a C_RNTI. Thereupon,the method includes interrupting the reception of a conventional commondata channel signal during a second time interval based on the mobilespecific identifier. Similar to the interruption of the multicasttransmission, the conventional common data channel signal may beinterrupted so that a measurement occasion may occur. Although, asdiscussed in greater detail below, due to differences between the firsttime interval and the second time interval, the mobile device mayreceive a conventional common data channel signal during a portion ofthe first time interval excluding the time of the second time interval.

FIG. 7 illustrates another embodiment of a method for interruptingtransmission of a multicast signal. The method begins, step 700 byreceiving channel configuration from a network, step 702. For example,as illustrated with respect to FIG. 4, the network 400 provides channelconfiguration information across connection 424 to the base station 416.The next step, step 704, is identifying a common channel of a selectedcommon physical channel with a largest transmission time interval.Similar to the functions performed by the mobile device 100, the largestcommon channel transmission time interval 122 is determined by thecommon channel selector 106. The next step, step 706, is calculating arepetition value using measurement occasion information acquired fromthe network, wherein similar to the embodiment discussed with respect toFIG. 1, the measurement occasion information 118 may be provided fromthe common channel selector 106.

The next step is using an assigned radio network temporary ID, therepetition value and the transmission time interval, to make adetermination if a system frame number corresponds with a measurementoccasion, step 708. Therefore, step 710, a decision is made if ameasurement occasion may occur with respect to a system frame number,step 710. If a measurement occasion may occur, the next step is toperform a channel measurement occasion, step 712. In the event ameasurement occasion cannot occur, the method proceeds to step 714including reading the selected common channel. In one embodiment, thecommon channel includes the conventional common data channel, whichcarries non-multicast data and may also include the multicast channelincluding multicast data.

The next step, step 716, is a determination if the transmission timeinterval is over. If the transmission time interval is not over, themethod reverts back to step 714 for reading the selected common channel.If the transmission time interval is over, the method proceeds to step708. Therefore, the mobile device uses the assigned radio network ID andmakes another determination if the system frame number corresponds witha measurement occasion. Thereupon, the method repeats through decisionstep 710 until the measurement occasion may be performed, step 712 andthereupon the method is complete, step 718. In another embodiment, themobile uses the repetition factor and the current system frame numberand largest transmission time interval, to determine the start of thenext transmission interruption time interval.

FIG. 8 illustrates a graphical representation of a system frame number800 of various system frames. In one embodiment, a timing sequence iscomposed of 4096 frames numbered 0-4095.

For reference with FIG. 8, FIG. 9 illustrates a common channel carryinguser data in the multiple system frames 900. The system frames 900 showconventional common data channel data frame units having an interval ofone system frame. Further illustrated in the system frames 900 of FIG. 9are identifiers for four separate sub-groups of mobile devices,specifically sub-group A 902, sub-group B 904, sub-group C 906 andsub-group D 908. As recognized by one having ordinary skill in the art,there may be any number of various sub-groups and the selection ofsub-groups 902, 904, 906 and 908 shown are for exemplary purposes andnot designated as being limiting herein.

FIG. 10 illustrates a graphical representation of multicast data frames1000 with a multicast data time interval 1002, which encompasses foursystem frames, thereby incorporating an interval in which all of thesub-groups A-D, 902, 904, 906 and 908, respectively, are associated. Asdiscussed above, FIG. 10 illustrates one exemplary embodiment of amulticast channel carrying multicast data with a single time intervalfor interruption of transmission, wherein the time interval occurs overa four frame interval. As recognized by one having ordinary skill in theart, any other suitable time interval may be utilized for the multicastdata.

FIG. 11 illustrates a graphical representation of a conventional commondata channel with a single sub-group, group A. The method and apparatusfor interruption of transmission of a multicast signal provides for amobile device to set its measurement occasion according to the timeintervals of transmission interruption for the multicast channel,because the multicast channel has, in this exemplary embodiment, atiming interval that is four times longer. Although, as represented inFIG. 11, when a mobile device in group A performs a measurement occasionwhich occurs for a single frame interval 1100, the time interval 1102 isunoccupied. Therefore, the mobile device performs the measurementoccasion during interval A 1100 and reads any available conventionalcommon data channels during the interval 1102. Therefore, transmissionbandwidth and system availability is not wasted during the three systemframes 1102 in which the multicast channel is interrupted formeasurement occasions, wherein group A performs its measurement occasionduring frame 1100.

FIG. 12 illustrates another embodiment wherein mobile devices may begrouped into two sub-groups, sub-group A 1200 and sub-group B 1202.Similar to the operations illustrated in FIG. 11, group A coordinatesits measurement occasions with respect to frames 1002 of FIG. 10 butalso reads communication data on available conventional common datachannels during the time intervals designated by 1202 and 1204, similarto interval 1102 of FIG. 11.

Furthermore, mobile devices in group B 1202 have a multicast timeinterval 1002 of FIG. 10 but only need to perform the measurementoccasion during the time frame designated 1202. Therefore, mobiledevices in group B 1202 may read data from the available conventionalcommon data channels during the time designated 1200 and 1204. As such,when multiple mobile devices are associated with different sub-groups,the active reading of conventional common data channels during intervalswhen the multicast channel has been interrupted allows for moreefficient usage of available conventional common data channel bandwidth.

It should be understood there exists implementations of other variationsand modifications of the invention and its various aspects, as may bereadily apparent to those of ordinary skill in the art and that theinvention is not limited by the specific embodiments described herein.For example, the number of sub-groups for mobile devices may be anysuitable number allowing for the efficient utilization and allocation ofresources to maintain an efficient utilization of bandwidth on a commonphysical channel. It is therefore contemplated and covered by thepresent invention, any and all modifications, variations, or equivalentsthat fall within the scope of the basic underlying principles disclosedand claimed herein.

1. A method for interrupting a reception of a multicast signal at awireless mobile communication device comprising: obtaining a commonidentifier; receiving a multicast signal; interrupting the reception ofthe multicast signal, by the wireless mobile communication device duringa first time interval based on the common identifier; wherein the firsttime interval is determined by a repetition factor assigned to thewireless mobile communication device; and performing a measurementoccasion during the time interval.
 2. The method of claim 1 furthercomprising: receiving a conventional common data channel transmissionduring a portion of the time interval.
 3. The method of claim 1 whereinthe step of obtaining includes: obtaining the common identifier througha broadcast message.
 4. The method of claim 1 wherein the step ofobtaining includes: obtaining the common identifier through a dedicatedmessage addressed to the wireless communication device.
 5. The method ofclaim 1 further comprising: obtaining a mobile specific identifier; andinterrupting the reception of a conventional common data channel signalduring a second time interval based on the mobile specific identifier.6. The method of claim 5 further comprising: receiving a conventionalcommon data channel signal during a portion of the first time interval.7. A wireless mobile device for interrupting reception of a multicastsignal, the apparatus comprising: a common channel selector operablycoupled to a receiver wherein the common channel selector is operativeto receive common data channel information therefrom; a repetition valuecalculator operative to receive measurement occasion information fromthe common channel selector and operative to calculate a repetitionfactor; a system frame number comparator operably coupled to therepetition value calculator and the common channel selector, the systemframe number comparator operative to receive the repetition factor fromthe repetition value calculator, a common identifier and a largestcommon channel transmission time interval from the common channelselector to determine if a measurement occasion should be performed; anda measurement occasion generator operably coupled to the system framenumber comparator and operative to receive a measurement occasioncommand signal such that the measurement occasion generator generates achannel measurement occasion.
 8. The wireless mobile device of claim 7wherein the common channel selector is operative to select one of aplurality of common channels on a common physical channel.
 9. Thewireless mobile device of claim 7 wherein the system frame numbercomparator uses the common identifier to determine if a measurementoccasion should be performed for any multicast service.
 10. The wirelessmobile device of claim 7 wherein the system frame number comparator usesthe common identifier to determine if a measurement occasion should beperformed for a single multicast service.
 11. A method for interruptinga transmission of a multicast signal, the method comprising: receiving achannel configuration signal from a network; identifying a commonchannel of a selected common physical channel where the common channelhas the largest transmission time interval; calculating a repetitionvalue using measurement occasion information acquired from the network;and determining if a system frame number corresponds with a timing of achannel measurement occasion using a radio network temporary identifier,the repetition value and the largest transmission time interval.
 12. Themethod of claim 11 further comprising: if the system frame numbercorresponds with the timing of the channel measurement occasion,performing a channel measurement occasion.
 13. The method of claim 11further comprising: if the system frame number does not correspond withthe timing of the channel measurement occasion, reading a selectedconventional common data channel.
 14. The method of claim 13 furthercomprising: determining if a transmission time interval is complete; ifthe transmission time interval is not complete, reading a selectedconventional common data channel; and if the transmission time intervalis complete, determining if the system frame number corresponds with thetiming of the channel measurement occasion.